Unequal income growth since the 1970s has buoyed the fortunes of the top 1 percent of income earners, widening income inequality in every state, the study from the Economic Policy Institute found. Across the country, the top-earning households took home 22 percent of all income in 2015, the latest year for which the IRS has data. That's just 1.9 percentage points lower than 1928's record share of 23.9 percent of income.

That 1928 peak has already been surpassed in New York, Florida, Connecticut, Nevada and Wyoming, EPI said.

Metropolitan regions that have leapfrogged over the 1928 record include Jackson, Wyoming -- home to the resort town of Jackson Hole -- and Naples, Fla, a popular retirement location.

The study also ranked 30 metropolitan regions where the top 1 percent now control more wealth than in the 1928 peak, including: